I decided to do the custom version; most of what I've done is showroom stock. I had some issues, but it came out to be one of the sharpest kits I've done.
If you use a coordinating color, the stripes look GOOD, but take your time. The decals need warm/hot water to release; otherwise, you're going to wait several minutes. The nice Chevy emblem decals are pretty, but they're some 20% TOO LARGE for the chrome emblems! (I used paint and a sharpened toothpick..)
I had to relocate the engine 2-3 mm forward in order to have it fit within the firewall; this caused other issues (bottom radiator hose not matching up, driveshaft almost too short, fan up against radiator). The distributor and coil had to disappear in order to get the engine to fit.
There's 2 lower tabs on the firewall that's supposed to cover the front of the frame; I never got them to fit right; they disappeared as well.
I was going to use some Cragar style mag wheels, but the diameter of the disc brakes was too large. I don't care much for large diameter wheels, but the ones with the kit came out nice.